Brush or wiper attachment for rotatable lap plates of a lapping machine



June 18, 1968 DAY BRUSH OR WIPER ATTACHMENT FOR ROTATABLE LAP PLATES OF A LAPPING MACHINE Filed July 23. 1965 9.44 INVENTOR.

United States Patent Oflice 3,388,504 Patented June 18, 1968 BRUSH OR WIPER ATTACHMENT FOR ROTAT- ABLE LAP PLATES OF A LAPPING MACHINE Lawrence Day, Chicago, Ill., assignor to Spitfire Tool and Machine Company, Inc., Chicago, Ill., a corporation of Illinois Filed July 23, 1965, Ser. No. 474,349 Claims. (Cl. 51-129) ABSTRACT OF THE DISCLOSURE A wiper brush attachment for a rotating lap plate of a lapping machine which is removably connected to the peripheral edge of the plate and extends downwardly therefrom into a well which houses the lap plate and in contact with the floor of the well to sweep contaminations off the floor and into a suitable drain.

Summary of the invention Flat lapping machines of the type now generally in use comprise a frame structure which supports an annular ring having formed as a part thereof an open well. Within this well adjacent its open top is rotatably supported a lapping plate. On this lapping plate is generally supported a wear ring within which is arranged a pressure plate disposed upon work contained within the wear ring. Generally the rotation of the wear ring and the pressure plate is induced by rotation of the lap plate. During the lapping operation, an abrasive compound is fed to the surface of the lapping plate. During the lapping operation the abrasive compound flows from the lapping plate over its peripheral edge portions onto the floor of the well. Such floor generally is tilted with respect to the horizontal so as to cause the abrasive compound received thereby from the lap plate to flow by gravity to and through a drain outlet.

The abrasive compound flowing into the Well deposits upon the floor of the well, dirt, grit, abrasive oil, and metallic particles. Eventually such deposits form a substantially hardened crust which, if not removed will interfere with the flow of the used abrasive compound to the drain opening. The removal of such crust and the cleaning of the well generally requires the removal of the lapping plate from the machine. As the lapping plate is usually of substantial weight, removal of the lapping plate is a laborious undertaking. During this removal of the lapping plate and the scraping of the deposits from the floor of the well, the lapping machine is necessarily out of service.

The invention has for its object the provision of a simple arrangement for constantly and continuously sweeping the surface of the floor of the well to sweep therefrom the above referred to accumulation and move the same with the used abrasive compound to the drain opening and thence into a sump bucket. The foregoing is accomplished without putting the machine out of service.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

FIG. 1 is a perspective view of a conventional lapping machine;

FIG. 2 is a fragmentary perspective view of the lap plate shown in its relation to a well within which it operates;

FIG. 3 is a fragmentary sectional detail view taken substantially on line 3-3 of FIG. 2;

FIG. 4 is a fragmentary sectional view taken substantially on line 44 of FIG. 3;

FIG. 5 is a perspective view of a modified form of wiper or sweeper embodied in my invention.

The lapping machine generally indicated at 10 in FIG. 1 comprises a base 11 which supports an annular ring 12. This ring 12 defines a well 13 having a floor 14. In the open top of the well 13 is rotatably supported in the conventional manner a lapping plate 15. On this lapping plate 15 is supported a retainer or wear ring 16 within which work to be lapped is placed. Generally there is disposed Within this retainer ring 16 a weight or pressure disc (not shown). The rotation of the work and the retainer ring is generally induced by rotation of the lap plate 15. To the lapping surface of the lap plate 15 there is delivered an abrasive compound. This compound flows onto the lapping plate during the lapping operation. It flows off the lapping plate 15 over its peripheral edge portion 17 into the well 13. As the floor of the well is tilted with respect to a horizontal plane, the lapping compound will flow by gravity to a drain outlet 14' and thence into a sump bucket (not shown.)

We find that during the lapping operation, there is an accumulation of dirt, grit, abrasive oil, and metallic particles within the well 13. If this accumulation is allowed to remain, it eventually becomes a substantially hardened crust which requires its manual removal therefrom. As hereinbefore stated, such removal requires lifting the heavy lap plate 15 from within the well.

My invention has to do with the automatic removal of dirt, grit, abrasive oil, metallic particles and the like from the floor of the 'well as such dirt, grit, abrasive oil and metallic particles drop thereon from the lap plate, and to keep the abrasive compound constantly flowing to the drain outlet 14', all during the operation of the machine.

In the preferred form of construction illustrated in FIGS. 2 to 4 inclusive, I accomplish the foregoing result by attaching as at 18 to the peripheral edge 17 of the lapping plate 15 a depending supporting arm 19, the major portion of its length being angularly formed in cross section to provide flanges 20 and 21. To the flange 20, adjacent its lower end portion there is pivotally connected as at 22 the stud shaft 23 of a brush 24. This brush 24 is formed of a plurality of flexible bristles 25 which are unaffected by oils for cleaning purposes or other cleaning solvents.

The bristles are maintained in sweeping or wiping contact with the floor 14 of the well 13 by a spring 26, one end of which is connected as at 27 to the flange 21 and the opposite end of which is connected as at 28 to the brush 24. This brush or wiper with its bristles bearing under the action of the spring 26 against the surface of the floor 14 will, while the lapping plate is rotating, sweep any and all dirt, grit, abrasive oil, and metallic particles from the surface of the floor 14 toward the drain outlet 14'. At the same time it will also induce the flow of the used abrasive compound toward the drain outlet and thence into the sump bucket (not shown). The stiffness of the bristles effects a constant sweeping and wiping action over the surface of the floor 14 which it contacts. As the spring urges the bristles into contact with the floor 14, the bristles will be spread fan-like (FIG. 3) so as to cover the area where the dirt, grit, abrasive oil, and metallic particles or the like have been deposited into the well 13. 1

By this simple arrangement, I have eliminated the requirement of stopping the operation of the machine and the laborious operation of periodically removing the lap plate for the purpose of manually scraping the accumulated dirt, grit, abrasive oil, and metallic particles from the well. By the use of my invention, such accumulation is removed while the machine is in operation.

By such simple arrangement, the used abrasive compound is kept constantly flowing from the well through the drain outlet and accumulations of dirt, grit, abrasive oil, and metallic particles and the like on the floor of the well are prevented.

In the modified form of construction shown in FIG. 5, parts which are similar to the preferred form of construction shown in FIGS. 2 to 4 inclusive are indicated by like reference numerals.

In the modified form of construction, the brush 24 is pivotally connected as at 29 to a depending flange 30 formed substantially at right angles to a flange 31. The flange 31 is attached by suitable attaching elements projected through openings 32, to the underside 33 of the lapping plate 15 adjacent the peripheral edge 17 thereof. The construction and the results accomplished by the form shown in FIG. is otherwise substantially the same as that of the preferred form shown in FIGS. 2 to 4 inelusive.

While I have found from actual experience that the life of the bristles 25 of the brush 24 extends over a substantial period of time, it is apparent that should it be necessary to replace the brush, all that is necessary to do is to remove the elements which attach the brush support to the lapping plate and then lift the brush and its support from the well.

The construction shown in the drawings and herein described is substantially simple and may be economically and easily attached to any conventional lapping machine of the type shown in FIG. 1 and herein described, without materially increasing the selling price of the lapping machine.

While I prefer to employ a brush having strong yet flexible bristles, it is obvious that there may be substituted for the bristles other materials which are not affected by cleaning solvents and oils and the like.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I therefore do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a lapping machine having a well defined by a circular side wall and floor, and a lapping plate having a diameter less than that of the well rotatably mounted substantially within the side wall and spaced above the floor of the well, an attachment comprising (a) a brush carried by and below the lapping plate and engaging the top surface of the floor of the well,

(b) means connecting said brush to the peripheral edge of the lapping plate for rotation therewith adjacent to the side wall and within the well,

(c) and means urging said brush into brushing and wiping contact with the floor of the well.

2. The device defined in claim 1 wherein the holding means is a spring having one end connected to the brush and the opposite end connected to the brush supporting means.

3. The device as defined by claim 1, wherein the brush comprises a plurality of flexible bristles resistant to the effects of cleaning oils and solvents.

4. The device defined in claim 2, wherein the brush comprises a plurality of flexible bristles resistant to the effects of cleaning oils and solvents.

5. The device defined by claim 1 wherein the brush supporting means is an arm attached to and depending from the peripheral edge portion of the lap plate.

References Cited UNITED STATES PATENTS 1,114,160 10/1914 Macbeth 5l263 X 2,180,952 11/1939 Gattoni 5l263 X 3,110,988 11/1963 Boettcher 51-131 3,110,992 11/1963 Keefe 51263 ROBERT C. RIORDON, Primary Examiner.

D. G. KELLY, Assistant Examiner. 

